Sydney, December 1988. Twenty-seven-year-old American mathematician Scott Johnson is found dead at the base of cliffs at North Head. He had moved to Australia to build a life with his partner, splitting his time between Canberra and Sydney while completing his PhD. His clothes are discovered folded near the cliff edge, and within months his death is ruled a suicide — but over the decades that follow, questions about that conclusion refuse to settle.

Sydney, July 1960. Eight-year-old Graeme Thorne disappears while waiting for a lift to school in Bondi. His family are ordinary — a travelling salesman, his wife, and their two children, living in a rented duplex. Three weeks earlier, however, Bazil Thorne had won £100,000 in the Opera House Lottery — and the media published their names and home address.

Police have unearthed a total of seven bodies when they conclude their search at Belanglo State Forest. Attention now turns away from the forest and toward finding who is responsible. Thanks to Paul Onions, a survivor of an earlier attack in the same forest, Task Force Air gets its breakthrough. On the 5th of May 1994, police fly Paul to Australia and show him a series of images. He identifies the man he says attacked him. His name is Ivan Milat.